The goal of this project is to determine the prevalence and adverse effects of comorbid depression in elderly patients with congestive heart failure (CHF). The specific aims are (1) to determine the prevalence and course of major depression in patients 65 years of age or older with CHF; (2) to determine the effects of depression in these patients on length of hospital stay, rehospitalization, institutionalization, cardiac morbidity, mortality, and quality of life; and (3) to identify potential mechanisms that may explain the adverse impact of depression on medical outcomes in heart failure patients, including altered autonomic nervous system activity, inadequate social support, nonadherence to dietary restrictions and medication regimens, increased medical comorbidity, and increased exposure to established risk factors. A random sample of 560 inpatients admitted for treatment of CHF will be recruited. During the initial hospital admission, data will be obtained on: (1) DSM-IIIR diagnosis and psychiatric history based on structured interview and current mood based on psychometric tests; (2) CHF etiology, chronicity, and severity; (3) other medical history including cardiac risk factors and comorbid chronic illnesses; (4) electrocardiographic variables; (5) social isolation, perceived social support, and quality of life. Adherence to the CHF medication regimen will be assessed for the first month following discharge, using an electronic monitor. Follow-up interviews and questionnaires will be administered at 1, 3, 6, 9, and 12 months post-discharge to assess rehospitalizations, changes in living arrangement, major cardiac events, and changes in psychiatric status, mood state, social situation, and quality of life. Rehospitalizations, cardiac endpoints, and other changes in health status will be confirmed by review of medical records. Planned analyses include (1) determination of the prevalence of depression;(2) comparison of depression prevalence between African-American and white patients; (3) survival analysis of the effects of depression on mortality rates; (4) modelling of the relationships among depression, social support, and quality of life; (5) logistic regression of readmission rate on behavioral and psychosocial predictors; (6) comparison of medication adherence rates between depressed and nondepressed patients; (7) comparison of electrocardiographic variables between depressed and nondepressed patients; and (8) analysis of the chronicity of depression.